1. General Technical Field of the Invention
This invention relates to CT tomographic imaging.
It is advantageously applied in cardiac imaging, but is not limited to this, and can also be applied in CT imaging of other organs.
2. Description of Prior Art
It is known that a conventional technique for acquiring images in CT tomography consists of injecting, in addition to the contrast product, a saline solution that is of higher density than the contrast product. If the acquisition is done on an organ—such as the heart, the saline solution pushes the contrast product into the cavities of the heart, and more specifically into the left cavity, thereby giving this cavity a greater contrast and a faster acquisition of images.
The images, which are thus clearer, have fewer artefacts, while the coronary artery is viewed with a very good contract.
However, this technique, which is now used by a large number of radiologists, has the major disadvantage of being incompatible with certain image processing operations conventionally performed following the acquisition (for example, and in a non-limiting manner for cardiac imaging: coronary analysis, functional analysis of the heart, detection of volumes, and so on).
Such processing operations indeed generally make it necessary to be capable of having a sufficient contrast. The segmentation of the heart requires, for example, a minimum contrast in each of the two cavities of the heart. However, the use of a saline solution tends to push all of the contrast product to the left cavity, and the right cavity is visible only with a much lower contrast. The resulting cardiac volume then does not contain the right cavities and coronary arteries.
FIG. 1 is a drawing of a cardiac image acquisition obtained with injection of a saline solution. This figure shows that the left cavity appears to be much more contrasted than the right cavity.
However, the current imaging system software is programmed today to systematically implement these post-processing operations, whether or not the practitioner needs to use saline solutions.
This results in a high error rate in the post-processing operations, which is unsatisfactory for practitioners.